Chronic constipation is a common disorder characterized by infrequent bowel movements, hard stools, and difficulty passing stool. It has been estimated that the prevalence of constipation in Western countries is as high as 27% (Jiang, C. et al., Acta Pharm. Sin. B 2015, 5:300-309). Constipation has traditionally been treated with fibers, osmotic agents, and stimulants, such as psyllium, polyethylene glycol, and bisacodyl, respectively. More recent approaches to treating chronic constipation include the use of serotonergic agents, chloride channel activators, and probiotics. In addition, antiopioids have been studied for the treatment of opioid-induced constipation (Ryu, H. S; Suck, C. C., Intest. Res. 2015, 1:297-305). Many of these new agents are administered systemically.
There is a need for new agents to treat constipation, in particular, agents which are effective for constipation due to a variety of causes. In addition, such agents which act locally in the colon with minimal side effects are particularly desirable.